Ammunition filler



United States Patent 3,389,028 AMMUNT'I'ION FlLLER Milton Roth, Rockaway, NJ, assignor to the United States of America as represented by the Secretary of the Army No Drawing. Original application Nov. 4, 1966, Ser. No. 592,682. Divided and this application July 13, 1967, Ser. No. 653,276

1 Claim. (Cl. 149-69) ABSTRACT 6F THE DESCLGSURE Dimensionally stable inert practice ammunition fillers which are compatible with high explosives, comprising, in the main, alums combined with cellulose or dextrin to lower the overall specific gravity of the alum combination, and with Basil, or Fe O to raise the overall specific gravity of the alum combination.

This invention is a divisional application of my copending patent application, Ser. No. 592,682, filed Nov. 4, 1966, entitled, Inert Filler, and relates to new compositions of matter and more particularly concerns practice ammunition having improved inert fillers which provide excellent dimensional stability characteristics.

Prior art practice ammunition generally contains a wax or other organic material such as polychlornaphthalene or castorwax which are noncrystalline, soften long before melting and expand and contract extensively with changes in temperature. Poor dimensional stability and strength characterize these waxes or organic compounds. Further, their coelficients of thermal expansion are such that, upon cooling, the tiller material shrinks from the shell walls and provides a loose charge having poor and non-reproducible ballistic properties. Additionally, polychlornaphthalene based filler materials are toxic in nature.

In bombs, shells, and the like, used for practice ammunition, high explosive charges are replaced by an inert material which duplicates the weight of the explosive. In addition to having the proper Weight for the volume occupied, the inert material should be capable of being loaded in the same manner and, desirably, with the same equipment used for explosives. In order to meet these requirements, the material should melt between 75 and 100 C. Furthermore, to permit reuse of the metal parts, the inert filter must be amenable to ready removal by washing with steam or hot water. The filler material should form a homogeneous mass upon cooling which will be free of voids, and yet readily admit of composition variations such that desired specific gravities from about 1.4 to 2.0 can easily and economically be attained. Most important, the inert material must have dimensional stability to prevent loose charges, exudation, or distortion of the container due to temperature changes. After meeting these requirements, it would be most desirable if the unit cost of the material was relatively low since very large quantities will be used. Finally, the filler material should be non-toxic, odorless, and compatible with such weil-known high explosives as RDX (cyclotrimethylene-trinitramine), HMX (cyclotetramethylenetetranitramiue) and TNT (2,4,6-t1initro-toluene).

It is, therefore, the principal object of this invention to provide compositions of matter having the aforementioned advantages.

Another object of the invention is to provide inert fillers for practice ammunition having the aforementioned advantages.

Other objects and features of the invention will become apparent as the invention is more fully hereinafter disclosed.

ING SPE CIFIO GRAVITIES [C0mposition, Wt. Percent] A1NH (SO .121120 Cellulose BaSOi Specific Gravity If desired, greater ranges or intermediate values may readily be obtained by one skilled in the art by varying the percentages above.

The ammonium alum is preferably rice to nut size and will have a melting point of about 935 C. The cellulose is a powdered, purified, wood type having a moisture content between 5 to 7%, a maximum of 1% being retained on a 35 mesh screen and a minimum of 96% passing through a 100 mesh screen (US. Standard Sieve). The BaSO, should have a specific gravity of about 4.40 and about 99.5% should pass through a 325 mesh screen (US. Standard Sieve).

Inorganic ingredients other than ammonium alum may be satisfactorily employed, a number of which are tabulated below:

TABLE IL-OOMPOUNDS USEFUL FOR INERT FILLERS AlK(SO -12H O is somewhat inferior to ammonium alum because the specific gravity is slightly less representative of explosives contemplated by this invention.

In lieu of cellulose, dextrin may be used advantageously to yield an inert filler having a lower specific gravity than the ammonium alum and Fe O may replace BaSO to provide an inert filler having a higher specific gravity than the ammonium alum.

In those instances where an undesirable chemical reaction may occur between the reactants and the cartridge casing, a corrosion inhibitor such as thiourea, octadecylamine, polyethanol rosinamine D, and the like, may be incorporated with the reactants in a proportion of about 0.5 to 1.0 part inhibitor to 100 parts of ammonium alum or its substitute.

Since certain applications for inert filler require contact with explosives, compatibility tests were conducted with many of the most widely and frequently used types. I have determined that any explosive based on TNT, RDX, or HMX may satisfactorily and safely be used in contact with my inert filler.

In the preparation of my inventive inert fillers, the ammonium alum will be melted by heating to about 100 C. in a stainless steel, glass, copper or other suitable vessel fitted with a mixer. If a stainless steel kettle is used for melting and mixing, a solution containing one part CuSO -5H O in four to six parts water for each 100 parts of ammonium alum must be used. Apply heat, by any suitable means, to the kettle containing the solution, start the mixer, and allow the inside walls of he "settle to :e wetted with the solution. lf glass. plastic. cooper. .Jl laQ- lined equipment is used. addition or The copper iiilrate solution may be omitted. Aluminum settles .nould 30t so used unless they are coated with a paint :ree :rom iron oxide, zinc oxide or aluminum. Throughout 'he melting and mixing, the kettle should be opened only while .naterial is being added in order to minimize evaporation or the steam that is evolved.

Now add the desired weight of alum. or ats substitute. rather slowly to the heated kettle containing he cooper sulfate solution so that the mixer will not :aeconie iverloaded. When all the alum has been added. continue the heating and stirring in the closed vessel until a clear liquid is obtained. Open the kettle. add the cellulose or aarium sulfate as rapidly as possible, again close the opening and continue mixing until a uniform dispersion appears to ac obtained. Generally, this Will require not more man ave minutes. Add the required weight of corrosion inhibitor. if necessary, replace the cover and mix for two [0 three minutes. The temperature or the mixture should be about 95 C.

Pour the mixture into shells or bombs which have previously been coated on their inner surfaces with in .1610 proof black paint or some other suitable coating 'VDlCll will prevent reaction or the molten mixture with the cartridge casing. Finally, allow the mixture to cool ilOWlV to room temperature.

It is apparent from the foregoing JCSCl'lDIiOll :hat l have provided new compositions of matter ideally suited for inert fillers for use in practice ammunition. :ne inert filler being dimensionally stable over a wide ranfle or temperature, low in cost. non-toxic. odorless. water music and compatible with HMX. RDX and TNT. The soecinc gravity of the tiller can be readily adjusted 'o simulate any explosive composition. Existing melting and cast loading equipment may still be used. Rapid solidification With aw shrinkage expedites the filling of bombs and shells.

he LOW uscositv or the molten filler assures complete .unrormitv :o the shape of the container into which it is Il OUIEG and the dimensional stability characteristics of my .omoosition assures adhesion to the walls of the article i .zontainer Within a temperature range of about 70 ll l90 F. Clean-up and disposal of excess filler is simple .no rapid 51X1C6 it can readily be dissolved and be washed .lulv with not water or steam.

Ji l! compositions are expected to lend themselves to inner applications. such, for example, as in ballasts, molds Lltd .DOGElS wherein a hard, castable, dimensionally table. inexpensive material of varying densities and colors night he desired.

claim:

11. .in ammunition filler comprising at least one memer EBKZCEEG :rom the group consisting of cyclotrimethllenetriizitramine. cyclotetramethylenetetranitramine and .e-trinitrotoluene, said filler being a substantially inert .JOlilDOSlIlOl'i or matter dimensionally stable over a temizerature canoe or about -70 to 190 F. and capable of ine iDSClilC gravities within limits of about 1.50 to N5. said .IOlIiDOSlilOl'l comprising, in combination therewith.

.th LDOI'QHHIC compound selected from the group conlatina or ilNH l'sO l -liZl-l O, AlK(SO -12H O, lllZlNOwlp'H O. Na B O IOH O, FeSO -7I-I O and hOl l8H O combined with a material for .llnnzina specific gravity of said inorganic compound n 1 value within said limits selected from the group nsistinn of cellulose, dextrin, BaSO and Fe O ll produce said inert composition.

llji references cited.

wEbUAlvllN R. PADGETT, Primary Examiner.

. .i. LECHERT. JR., .lssz'slant Examiner. 

